# There are n #>=# 11 people. Set A must have 10 people. Set B must have 11 people. A person may belong to both A and B at the same time. How many ways can this be done?

##### 1 Answer

Jan 23, 2018

#### Explanation:

We're working with combinations, the general formula of which is:

We have a population of

To test this, let's set